I would extend "file browser" to be the more general "tree navigation" - for instance, Miller Columns[1] (which I believe is an accurate characterization of Haxplore's interface) are used in the Pharo environment[2] to navigate objects.
In general, though, I agree with you - I think that most of the media tools that we use today could benefit from Miller Columns and a keyboard-driven design....
I'm interested in talking about UI affordances for power users - would you be interested? If so, drop me an email (you don't have your email in your HN profile, and in-thread discussion isn't a good use of HN space).
Hi. Thank you for leaning in, sharing your ideas. I'll check out Pharo. Peeking at it, it reminds me of a Smalltalk dev env. Cool.
1. Navigation
For navigation, my blue sky notion is to have ad hoc hierarchies. So imagine allowing the user to reorder those Miller columns. And any metadata item can be used as a column. And then the hierarchy browser (Finder equiv) infers the new tree.
This is probably called faceted navigation.
So in the case of Haxplore, the columns for one nav view I want are 'Author', 'Date', 'Kind' (eg OC, Show, Ask).
For music, I want a nav view to sort by Producer.
For movies, views for Director and Writer.
For podcasts, views for Guests and Topic.
Any way, you get the idea.
2. Filtering
All nav views should have filters. (I forget which IDE allowed this.)
Not just Spotlight style results, or Amazon style faceted product searches.
Because I still want to drill down thru the resultset using Miller columns.
3. Quantified Self
Log all the activity and metrics client side.
For podcasts and audio books, log when and where I was.
For all content, record if I looked at it, how long I looked at it, if I just deleted or skipped, etc. My count of podcast subscriptions is ridiculous. But I'm afraid (FOMO) of deleting something I liked. My own metrics would help me manage my consumption.
Creating ad hoc 'follow' subscriptions would be cool too. Remember HN commenters I liked. The podcast guests I liked. Ditto producers and directors.
This is kinda how I imagine all my clients should work. HN, feedly & NetNewsWire, Overcast & Podcast.app, Music.app.
It's like a synthesis of file explorers and media consumption.
Bravo.
(I've got a bunch of other UX notions for power users.)